In a vehicle that is mounted with a plurality of power sources including a secondary battery, such as a hybrid vehicle, secondary battery cells produce heat because of current passing through the battery during charge and discharge, internal resistance of the battery cells, and contact resistance of cell connectors. Temperature of the secondary battery greatly affects a life of the secondary battery. Blowing air of ordinary temperature or the like for cooling the battery cells or warming the battery cells under extremely low temperature conditions is very important in improving output of a battery system and reducing a number of cells.
However, securing internal space of the vehicle sets a limit to securement of a sufficiently ample mounting area for the secondary battery, so that the plurality of battery cells is arranged inside a housing of limited size. Air-blowing using a forced air-cooling means for air-cooling is generally carried out to temperature-condition the secondary battery which is an object to be temperature-conditioned. It is a matter of course that increase in output density of the battery demands increase in output of a device such as a temperature conditioning unit and a temperature conditioning system. The increase in the device's output tends to cause increase in size of the device. On the other hand, there is a demand for size reduction of the device. Thus, it goes without saying that seeking the increase in the device's output and the size reduction of the device at the same time is a highly difficult subject.
A centrifugal blower that uses a scroll casing, such as shown in PTL 1 or PTL 2, is often used in a conventional cooling device for a vehicle-mounted secondary battery. In the centrifugal blower using the scroll casing, a casing exit requires a measurable straight passage. Accordingly, a distance from a housing to the blower increases, so that an ample mounting area is required. Moreover, a flow discharged from an impeller (centrifugal fan) is drawn outward along a scroll side wall. For this reason, a flow uniforming mechanism such as a flow dividing duct is required to uniform temperature distribution inside the housing. These points are problematic when further size reduction is sought.
FIG. 18 is a sectional view illustrating a temperature conditioning unit of a comparative example. Object 350 to be temperature-conditioned is accommodated by housing 310 of the temperature conditioning unit of the comparative example shown in FIG. 18. Air discharged from forward-curved fan 400 is integrated circumferentially inside scroll casing 1120. Scroll casing 1120 is such that a distance from rotating shaft 1112a to side wall 1121 gradually increases. Thus, flow 301 of the air discharged from forward-curved fan 400 is drawn toward inner-circumferential surface 1121a of side wall 1121. Accordingly, flow uniforming mechanism 1310 such as duct 1311 needs to be mounted inside housing 310 to uniform air flow 301 that is fed into housing 310.
However, centrifugal blower 1100 using forward-curved fan 400 causes long distance L from its center of gravity G to discharge hole 1123. Temperature conditioning unit 1010 thus becomes badly balanced and unstable when this centrifugal blower 1100 is mounted to housing 310. Accordingly, temperature conditioning unit 1010 is fixed to a peripheral member via mounting parts 1124. In this case, a variety of shape variations are required of mounting parts 1124 for adaptation of temperature conditioning unit 1010 to an environment where temperature conditioning unit 1010 is used.
Especially in cases where flow uniforming mechanism 1310 is formed separately from housing 310, a distance from center of gravity G to flow uniforming mechanism 1310 needs to be considered. Generally, the distance from center of gravity G to flow uniforming mechanism 1310 becomes long, so that the temperature conditioning unit becomes more badly balanced.
In a conventional method, a blower mechanism is disposed near a heat generator when air is blown against object 350 to be temperature-conditioned (refer to, for example, PTL 3). However, in an electric apparatus in which an object to be temperature-conditioned is large with respect to a housing with a plurality of heat generators being densely disposed, air flow resistance, that is to say, pressure loss increases.
In a conventional temperature conditioning unit, a housing has high ventilation resistance, so that high output is required of a blower mechanism, thus naturally causing increase in size of the blower mechanism. Consequently, the blower mechanism is difficult to accommodate in the housing. As such, a blower mechanism is generally placed externally to a housing, and a passage is formed by a duct or the like that connects a discharge hole of a blower and an inflow port of the housing (refer to, for example, PTL 1). For this reason, it is difficult to achieve size reduction of the electric apparatus including the object to be temperature-conditioned and a temperature conditioning system.